Could acne be prevented with a vaccine?
Researchers are testing vaccines that target inflammatory skin bacteria, raising the possibility of preventing acne rather than just treating it.
- 10 March 2026
- 6 min read
- by Linda Geddes
At a glance
- A vaccine that can protect against acne has entered early-stage trials. Using mRNA technology, the vaccine targets specific strains of the C. acnes bacterium and the inflammatory pathways thought to drive it.
- Acne is one of the most prevalent diseases worldwide, with about 85% of adolescents affected, and it is increasing in prevalence in adults.
- If successful, acne vaccines could mark the beginning of a new class of vaccines designed not just to stop infections, but to recalibrate the complex relationships between microbes, the immune system and chronic conditions.
Acne may seem an unlikely candidate for a vaccine.
It’s not an infectious disease like measles or influenza, and while its consequences can be visibly disfiguring, it rarely threatens lives.
Yet researchers are now trying to prevent it. In recent months, a vaccine candidate from Sanofi entered early-stage clinical trials, while other groups are developing experimental vaccines designed to blunt the inflammatory effects of skin bacteria.
These efforts reflect a broader shift in vaccine research. Instead of targeting only fast-spreading infectious diseases, scientists are increasingly exploring vaccines that could modify chronic conditions by neutralising specific molecules, microbes or inflammatory pathways.
“We’re entering an age where many of the pathogens we want to target are more commensal,” says Prof George Y. Liu at the University of California in San Diego, US, referring to microbes that normally live on the body but can sometimes contribute to disease.
Acne, an inflammatory condition shaped by interactions between skin bacteria, hormones and the immune system, has become an early testing ground for this approach in dermatology, raising the possibility that vaccines might eventually be used to prevent or blunt other skin diseases caused by microbes or the immune response to them.
What causes acne?
Acne is a very common, chronic inflammatory skin condition that affects hair follicles and the oil-producing glands connected to them. During puberty and adulthood, hormones called androgens stimulate the production of an oily substance called sebum. Excess sebum and dead skin cells can clog hair follicles, forming blockages known as blackheads or whiteheads.
“A bacterium called Cutibacterium acnes proliferates in this oil-rich environment and releases inflammatory mediators, leading to papules, pustules, cysts and nodules,” says Dr Hazel Oon, head of the Psoriasis Unit and Acne Clinic at the National Skin Centre in Singapore. “Eventually, these can form red or brown dyspigmented macules [areas of discoloured skin] and scars.”
Although acne isn’t life-threatening, it can still have a profound impact on people’s lives. “Acne is one of the most prevalent diseases worldwide, with about 85% of adolescents affected, and adult acne – acne at age 25 and above – is increasing in prevalence,” says Oon.
Severe or poorly treated acne can cause permanent scarring and skin discolouration and can affect mental health, contributing significantly to the global burden of disease, she added.
What’s wrong with current acne treatments?
For decades, acne has been treated with creams, antibiotics and oral drugs like isotretinoin: therapies aimed at controlling breakouts and preventing scarring, rather than preventing the condition from developing in the first place.
“To date there is still no safe and effective treatment that can prevent and cure this disease,” Sanofi says.
Topical and oral antibiotics can also lead to antibiotic resistance and disrupt the gut microbiome, and while isotretinoin can be highly effective, it carries risks and requires regular monitoring. Better treatments are therefore needed that offer reliable long-term results, are easy to use and safe.
How do experimental acne vaccines work?
Sanofi’s candidate is an mRNA-based vaccine designed to target specific strains of C. acnes linked to the condition, and the inflammatory pathways thought to drive it.
“The goal is that this treatment will help restore healthy skin microbiome balance, reduce inflammation and lesions with a favourable safety profile in addition to longer-lasting results, while reducing the need for repeated courses of antibiotics or other medications,” says Oon, who is involved in the early human trials.
Although C. acnes is a normal inhabitant of healthy skin, strains associated with acne produce higher levels of molecules known as virulence factors – proteins that can trigger inflammation in blocked follicles. Sanofi hasn’t disclosed exactly which antigens its vaccine targets, but the hope is that neutralising these factors could lead to fewer and less inflamed acne lesions.
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“Unlike antibiotics, this highly selective targeting avoids broad disruption of the skin microbiome,” says Oon. Trial participants’ skin microbiomes will be monitored to confirm this.
Sanofi’s isn’t the only acne vaccine in development. Several research groups, including Liu’s, are exploring vaccines that target virulence factors produced by C. acnes, rather than eliminating the bacterium itself.
Liu’s group recently identified an enzyme produced by acne-associated strains of C. acnes, called HylA, that appears to drive inflammation in the skin. The team is now developing experimental strategies, including a vaccine, to neutralise the enzyme, reducing inflammatory responses.
“The vaccine targets this pro-inflammatory enzyme and not the bacteria,” Liu says. This approach could, in principle, reduce inflammation while preserving the broader skin microbiome.
When are acne vaccines likely to become available?
Sanofi’s vaccine candidate is currently being tested in early Phase 1/2 clinical trials at multiple sites worldwide, including in the United States, Canada, Australia and Singapore. In Singapore, two doses of the vaccine are being tested in adults with mild acne to assess safety, tolerability and whether the vaccine induces a robust and durable antibody response. Other countries are evaluating up to three doses in adults with moderate to severe acne.
Researchers are also examining whether the immune response reduces inflammatory signalling linked to acne while preserving beneficial skin microbes, says Oon.
A long-term extension study is also planned to assess how durable any protective effect may be.
Even if the results are promising, acne vaccines are unlikely to reach patients quickly. Early-stage trials primarily assess safety and immune responses, and successful candidates would still need to pass larger Phase 2 and 3 trials before regulatory approval, a process that can take several years.
Regulators, clinicians and patients will also need to weigh the benefits of prevention against the risks of vaccinating against a condition that is rarely life-threatening. “Most acne treatment is aimed at treating active acne and scarring rather than preventing disease,” says Oon.
Decisions about new therapies will depend not only on efficacy and safety, she adds, but also on the broader burden of the condition, including the costs of long-term medications, ongoing monitoring for drugs such as isotretinoin, antibiotic resistance, clinic visits and the daily burden of topical treatments.
What other skin conditions could vaccines potentially target?
Acne is only one of several skin conditions that researchers are exploring for vaccine-based prevention or treatment. According to Oon, who recently reviewed some of these approaches, the World Health Organization has identified several pathogens linked to skin disease as priorities for vaccine research under its Immunization Agenda 2030.
Some of the most advanced efforts focus on neglected tropical diseases such as leishmaniasis, which causes chronic skin ulcers. At the same time, vaccines already exist for several diseases that affect the skin, including measles, chickenpox, shingles and human papillomavirus (HPV). Maintaining high vaccination coverage for these conditions remains critical, Oon says.
Researchers are also exploring whether vaccines could help control inflammatory skin diseases such as atopic dermatitis, which is often associated with colonisation by Staphylococcus aureus. But developing vaccines against the bacterium has proved difficult. “There have been more than ten clinical trials of S. aureus vaccines, and they have all failed,” Liu says.
But advances in understanding how microbes interact with the immune system are opening new possibilities. Instead of trying to eliminate bacteria entirely, many of the newest approaches aim to disarm the specific factors that trigger inflammation.
If successful, acne vaccines could mark the beginning of a new class of vaccines designed not simply to stop infections, but to recalibrate the complex relationships between microbes, the immune system and chronic conditions.
